1. Field of the Invention
The present invention relates to a printing device, printing method, and printing control program product.
2. Description of the Related Art
The way humans see colors when colors are represented by ink on printing paper can be expressed as the product of the color-matching function (including the characteristics of the human eye), the reflectance of the ink and printing paper, and the spectral distribution of the light source. Printing devices normally represent colors through a combination of C (cyan), M (magenta), and Y (yellow) or similarly colored inks such as lc (light cyan) and lm (light magenta), and colors can therefore be said to look different as a result of changes in the spectral distribution of the ink in the product of the elements which govern the way colors appear, as described above. The CMY colors are combined as needed and printed onto printing paper to represent achromatic grays or any other color.
In such printing devices, colors are printed with reference to a predetermined relationship between combinations of ink and image data based on colors measured under a certain light source. Although colors must be measured under a certain light source since they are represented as the aforementioned product, when the printed results are seen under a different light source than the light source under which the colors were measured, the colors end up looking different. This phenomenon is particularly pronounced with low chromatic or achromatic grays. For example, colors that look gray in sunlight can appear to be imbued with color under indoor lamp light. Techniques have thus been proposed to minimize such changes in color as a result of changes in the light source (such as Japanese Unexamined Patent Application (Kokai) 2002-225317). Changes in the way colors appear are more pronounced with pigment-based inks.